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Electricity From Salty Water
BuzzSkyline writes "It's possible to produce energy by simply mixing fresh and salty water. Although chemists and physicists have long known about the untapped energy available where fresh water rivers pour into salty oceans — it's equivalent to 'each river in the world ending at its mouth in a waterfall 225 meters [739 feet] high' — the technology for exploiting the effect has been lacking. An Italian physicist seems to have solved the problem with the experimental demonstration of a 'salination cell' that creates power given nothing more than input sources of salty and fresh water. The researcher believes that this renewable, environmentally friendly energy source could be deployed in coastal areas and could provide another addition to the green-tech roster. A paper describing the technology is due to be published in an upcoming issue of the journal Physical Review Letters."
Don't bother. PETA and Greenpeace both called and said it'll kill too many endagered fish species.
While PETA and Greenpeace may have different definitions of "too many" than you do, balancing concern about impacts on fish stocks with concerns about energy is a perfectly reasonable thing to do, given that fish are part of our food supply (and food chain).
There's also issues like whether or not a given fresh water supply might have better uses.
Tweet, tweet.
It produces less (laws of thermodynamics are a bitch). But you point out an interesting way to describe it to people. i.e. It takes energy to desalinate sea water, this process is sort of like running desalination in reverse to generate energy.
The world is made by those who show up for the job.
There are serious transportation issues with piping potable water from places where it is plentiful to places where it is needed. That's WHY we have a potable water crisis in some areas (especially the American Southwest) while we have no problem whatsoever in others (like the Northeast or the mouth of the Missisippi). In those places there's already huge amounts of water flowing into the ocean. This technology would allow that water that is already being mixed with ocean water to generate electricity in the process.
Also there are situations where water is not potable due to issues other than salinity, and for the purposes of this process might be considered "fresh" compared to saline water.
An interesting thing would be if this could be used to provide for cheap solar power - Some of the largest "solar power" we use today are salt concentration ponds - they don't provide electrical power BUT they do provide the function of separating salt from water in large solar ponds. It would be horrendously inefficient per unit of surface area, but the cost is so low that large surface areas could be achieved.
retrorocket.o not found, launch anyway?
If you RTFA (pardon me, I forgot this is SlashDot) the same effect can be gotten by mixing salt water with more highly salinated water (made by evaporating sea water - say, using a solar evaporation pool) or lightly polluted water (non-potable).
I could also venture a guess, based on the fact this is a solution postulated for coastal locations, that the process could also be sited at or near the mouth of a river - say one the empties into the sea or ocean? In that case only fresh water that was destined to end up mixed into salt water would be used.
...carrier dead.....
"Brogioli maintains that his salinity cell could be ramped up faster than other salination approaches and could be made as affordable as solar power in a decade or so."
As affordable as Solar in a decade? Solar's main problem now is it's cost!
Energy on the planet doesn't just SIT there doing nothing.
Of all the highly concentrated nonsense in your post, this is the highest peak of wrong-headedness.
Just to take a single example: what is the quantum efficiency of photosynthesis reactions?
Energy goes to waste all over the place--it would, amongst other things, be impossible to see if it did not! Nature is unbelievably wasteful. The very fact of the existence of oil and coal reserves is testament to this: those beds were all huge amounts of available energy at the time the dead plant matter was deposited. It did indeed "just sit there" on the surface for thousands of years as it accumulated before being buried.
Energy is "just sitting there" accumulating in peat bogs as I write this, freely available for some magic unicorns or something to come along and use it. I don't see any, do you?
Finally, your bizarre claim that any change to ocean temperature whatsoever is "enough to disrupt the ecosystem" will stand as a monument to the dangers of innumeracy for generations to come.
Blasphemy is a human right. Blasphemophobia kills.
Don't bother. PETA and Greenpeace both called and said it'll kill too many endagered fish species.
Fish? Oh, you mean sea kittens.